Computer-aided design finite element modeling of different approaches to rehabilitate endodontically treated teeth

Abstract

Background: Carious lesions and dental fractures cause weakening in the dental structure. In these situations, endodontic treatment and prosthetic rehabilitation using an intraradicular post are indicated. However, the postspace preparation of the root canal further weakens the dental remnant, especially if there is no ferrule present. This study aimed to evaluate the stress distribution in endodontically treated upper premolars treated with different rehabilitation approaches. Materials and Methods: An endodontically treated first upper premolar was modeled for finite element analysis. Three different approaches were carried out on this model: rehabilitation with fiberglass post (FCP), endocrown (ECW), or buildup. The models were exported in STEP format to the analysis software (ANSYS 17.2, ANSYS Inc., Houston, TX, USA). The solids were considered isotropic, homogeneous, and linearly elastic. A mechanical, structural static analysis was used as the criterion of maximum principal stress to show regions under tensile stress to evaluate the stress distribution in the restoration, cementation line, and root. A load of 400 N (90°) was applied to the lingual triangular ridge. The values of maximum principal stress in MPa were evaluated through colorimetric graphs. Results: Similar stress concentration was observed for all groups. However, the ECW group presented higher values in the restoration/cement interface and root dentin. Conclusions: All the treatment modalities had favorable mechanical behavior to support the masticatory loads; nevertheless, the ECW group presented a higher risk of detachment failure.

Effect of Restorative Material on Mechanical Response of Provisional Endocrowns: A 3D—FEA Study

“…Observing the present results, the use of resin composite could offer to the patient and to the clinician a more reliable option in terms of marginal misfit and adhesive failure risk [ 24 ]. According to the literature [ 10 ], comparing different postendodontic treatments, the endocrown is able to promote higher tensile stress at the cement layer and in dentine, which increases the risk of failure by debonding [ 10 ]. The present study has complemented these findings, indicating that the provisional material can affect the endocrown mechanical response and should be selected in order to reduce the adhesive failure risk.…”

“…One of the largest restoration volumes that can be used to restore a tooth is the endocrown design [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. This restoration modality has emerged as a more conservative, quick, and easy-to-assemble approach, in which the build-up and crown integrate into a single structure and can be manufactured by computer-aided design using the pulp chamber as part of their mechanical retention [ 6 ].…”

“…Since the adhesive surface between abutment teeth and endocrowns is extended using micro-mechanical retention, the transmission of forces to dental abutments can be improved in comparison with a full crown [ 7 ]. However, this approach requires the presence of healthy cervical enamel and an adequate endodontic treatment in the abutment tooth [ 10 ].…”

“…Several studies have been carried out investigating the restorative material used to perform the endocrown treatment, reporting the use of ceramics, nanocomposites, and hybrid materials [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. In addition, clinical cases reported the use of acrylic resin [ 15 ], resin composite [ 16 ], and bis-acrylic resin [ 17 ] as restorative material for the manufacturing of interim endocrowns.…”

“…In order to understand the biomechanical behavior of endocrown restorations and the influence of restorative materials, a numerical simulation can be performed using the finite element method (FEM). This method has been extensively reported in literature, with previous studies that have evaluated this treatment modality [ 5 , 7 , 8 , 9 , 10 , 14 , 18 , 19 ]. As advantages, the FEM is able to identify problems by assessing the state of stress and deformation of materials and adhesive interfaces, evaluating the stress distribution generated by masticatory loads with model standardization, and offering an acceptable approximate solution [ 20 , 21 , 22 ].…”